以下代码是对图像进行骨架提取的函数:
cpp
void thinImage(cv::Mat& src, int maxIterations)
{
assert(src.type() == CV_8UC1);
cv::Mat dst(src.size(), src.type());
int width = src.cols;
int height = src.rows;
for (int i = 0; i < height; i++)
{
uchar* ptr = src.ptr<uchar>(i);
for (int j = 0; j < width; j++)
{
if (ptr[j] > 0)
{
ptr[j] = 1;
}
}
}
src.copyTo(dst);
int count = 0; //记录迭代次数
while (true)
{
count++;
if (maxIterations != -1 && count > maxIterations) //限制次数并且迭代次数到达
break;
std::vector<uchar*> mFlag; //用于标记需要删除的点
//对点标记
for (int i = 0; i < height; ++i)
{
uchar* p = dst.ptr<uchar>(i);
for (int j = 0; j < width; ++j)
{
//如果满足四个条件,进行标记
// p9 p2 p3
// p8 p1 p4
// p7 p6 p5
uchar p1 = p[j];
if (p1 != 1) continue;
uchar p4 = (j == width - 1) ? 0 : *(p + j + 1);
uchar p8 = (j == 0) ? 0 : *(p + j - 1);
uchar p2 = (i == 0) ? 0 : *(p - dst.step + j);
uchar p3 = (i == 0 || j == width - 1) ? 0 : *(p - dst.step + j + 1);
uchar p9 = (i == 0 || j == 0) ? 0 : *(p - dst.step + j - 1);
uchar p6 = (i == height - 1) ? 0 : *(p + dst.step + j);
uchar p5 = (i == height - 1 || j == width - 1) ? 0 : *(p + dst.step + j + 1);
uchar p7 = (i == height - 1 || j == 0) ? 0 : *(p + dst.step + j - 1);
if ((p2 + p3 + p4 + p5 + p6 + p7 + p8 + p9) >= 2 && (p2 + p3 + p4 + p5 + p6 + p7 + p8 + p9) <= 6)
{
int ap = 0;
if (p2 == 0 && p3 == 1) ++ap;
if (p3 == 0 && p4 == 1) ++ap;
if (p4 == 0 && p5 == 1) ++ap;
if (p5 == 0 && p6 == 1) ++ap;
if (p6 == 0 && p7 == 1) ++ap;
if (p7 == 0 && p8 == 1) ++ap;
if (p8 == 0 && p9 == 1) ++ap;
if (p9 == 0 && p2 == 1) ++ap;
if (ap == 1 && p2 * p4 * p6 == 0 && p4 * p6 * p8 == 0)
{
//标记
mFlag.push_back(p + j);
}
}
}
}
//将标记的点删除
for (std::vector<uchar*>::iterator i = mFlag.begin(); i != mFlag.end(); ++i)
{
**i = 0;
}
//直到没有点满足,算法结束
if (mFlag.empty())
{
break;
}
else
{
mFlag.clear();//将mFlag清空
}
//对点标记
for (int i = 0; i < height; ++i)
{
uchar* p = dst.ptr<uchar>(i);
for (int j = 0; j < width; ++j)
{
//如果满足四个条件,进行标记
// p9 p2 p3
// p8 p1 p4
// p7 p6 p5
uchar p1 = p[j];
if (p1 != 1) continue;
uchar p4 = (j == width - 1) ? 0 : *(p + j + 1);
uchar p8 = (j == 0) ? 0 : *(p + j - 1);
uchar p2 = (i == 0) ? 0 : *(p - dst.step + j);
uchar p3 = (i == 0 || j == width - 1) ? 0 : *(p - dst.step + j + 1);
uchar p9 = (i == 0 || j == 0) ? 0 : *(p - dst.step + j - 1);
uchar p6 = (i == height - 1) ? 0 : *(p + dst.step + j);
uchar p5 = (i == height - 1 || j == width - 1) ? 0 : *(p + dst.step + j + 1);
uchar p7 = (i == height - 1 || j == 0) ? 0 : *(p + dst.step + j - 1);
if ((p2 + p3 + p4 + p5 + p6 + p7 + p8 + p9) >= 2 && (p2 + p3 + p4 + p5 + p6 + p7 + p8 + p9) <= 6)
{
int ap = 0;
if (p2 == 0 && p3 == 1) ++ap;
if (p3 == 0 && p4 == 1) ++ap;
if (p4 == 0 && p5 == 1) ++ap;
if (p5 == 0 && p6 == 1) ++ap;
if (p6 == 0 && p7 == 1) ++ap;
if (p7 == 0 && p8 == 1) ++ap;
if (p8 == 0 && p9 == 1) ++ap;
if (p9 == 0 && p2 == 1) ++ap;
if (ap == 1 && p2 * p4 * p8 == 0 && p2 * p6 * p8 == 0)
{
//标记
mFlag.push_back(p + j);
}
}
}
}
//将标记的点删除
for (std::vector<uchar*>::iterator i = mFlag.begin(); i != mFlag.end(); ++i)
{
**i = 0;
}
//直到没有点满足,算法结束
if (mFlag.empty())
{
break;
}
else
{
mFlag.clear();//将mFlag清空
}
}
dst.copyTo(src);
for (int i = 0; i < height; i++)
{
uchar* ptr = src.ptr<uchar>(i);
for (int j = 0; j < width; j++)
{
if (ptr[j] > 0)
{
ptr[j] = 255;
}
}
}
}